GAZA CITY, Gaza Strip >> A senior PLO official proposed a 24-hour humanitarian cease-fire Tuesday in the Gaza war, saying he spoke in the name of Hamas, but was contradicted a short while later by a spokesman of the Islamic militant group.

In Gaza, a health official said at least 100 Palestinians were killed in Israeli airstrikes and tank shelling Tuesday, as Israel escalated its military campaign. The official, Ashraf al-Kidra, said the day’s death toll was expected to rise.

There have been several instances in which the daily Gaza death toll in more than three weeks of Israel-Hamas fighting has surpassed 100.

Israel has lost 53 soldiers, along with two civilians and a Thai national.

Tuesday’s cease-fire offer was made by the Palestine Liberation Organization, of which Hamas is not a member. The largest group in the PLO is the Fatah movement of Palestinian President Mahmoud Abbas, Hamas’ main political rival.

However, the PLO’s secretary-general, Yasser Abed Rabbo, said the offer came after consultations with Hamas and Islamic Jihad, a smaller militant group in Gaza. Palestinian officials said Abbas has been in touch in recent days with Khaled Mashaal, the top Hamas leader in exile.

“The Palestinian leadership, following consultations with the leadership in Hamas and Islamic Jihad, announces in the name of all of these our readiness for an immediate humanitarian cease-fire for 24 hours,” Abed Rabbo said in the West Bank.

A Hamas spokesman in Gaza, Sami Abu Zuhri, said that “the remarks of Mr. Abed Rabbo are not true and have nothing to do with the positions of the factions at the moment.”

It was not clear if Abu Zuhri reflected the views of the Hamas leadership in exile.

In Israel, government spokesman Mark Regev declined comment.

Tuesday’s strikes came after Israeli Prime Minister Benjamin Netanyahu on Monday warned of a “prolonged” campaign against Hamas. It was not clear if this meant Israel has decided to go beyond the initial objectives of decimating Hamas’ ability to fire rockets and demolishing the group’s military tunnels under the Gaza-Israel border.

Already, the intensity and the scope of the current Gaza operation is on par with an invasion five years ago, which ended with a unilateral Israeli withdrawal after it hit Hamas hard.

Gaza’s power plant also was forced to shut down Tuesday after two tank shells hit one of three fuel tanks, said Jamal Dardasawi, a spokesman for Gaza’s electricity distribution company. He said the damage would take months to repair.

Even before the shutdown, Gaza residents only had electricity for about three hours a day because fighting had damaged power lines.